(IDEX Online) - Two diamonds over 100-carats lead a Sotheby's New York auction next month - a 101.41-carat Type IIa pear-shaped D-color IF stone, which is expected to sell for over $10m.And a 111.59-carat pear-shaped fancy deep orange-brown diamond, on the market for the first time in nearly 40 years, with an estimate of $1.5m to $2.5m.Sotheby's says it is "pleased to present not one, but two of earth's rarest treasures" at its Magnificent Jewels live auction on 16 June.The first stone, named Juno, is set to become only the 12th +100-ct D-color diamond ever to sell at auction, and it is the fourth-largest pear diamond to be offered at auction.The second, dubbed the Earth Star, was cut from a +248-cts rough gem discovered at the Jagersfontein mine, South Africa, in 1967. It sold for nearly $1m in 1983 and has remained in private hands ever since.Pic shows Juno and the Earth Stone.